This invention pertains to exercise apparatus, and more particularly to exercise rowing or sculling machines The invention is more specifically directed to a rowing or sculling machine which simulates the sweeping, rowing motion characteristic of a rowing or sculling shell, and which imparts a resistance to the pull of the oars similar to that of an actual rowing or sculling shell.
Typical rowing machines have employed friction brakes or hydraulic resistance devices to simulate the drag resistance met by the oars in water. In these machines, the friction or hydraulic resistance devices are incorporated as part of an oar lock and form the pivot for the simulated oars. Typical rowing machines are illustrated in U.S. Pat. Nos. 3,528,653 and 1,111,269. These rowing machines provided, at best, a crude sensation of rowing, and it was difficult or impossible to set the resistance accurately. The amount of resistance in these machines can change over time, as the device ages. Because it is not possible to control the resistance to the sweep of the oars, and thus cannot program exercise stress for the individual, these rowing machines do not permit optimum use in an exercise training program.
A different approach to a stationary rowing machine was taken in U.S. Pat. No. 4,396,188. With that rowing machine, a flywheel with air vanes translates air movement resistance into resistance to a rowing stroke-like motion. The machine of U.S. Pat. No. 4,396,188 operates by a chain which is pulled to rotate the flywheel. The subject rower sits on a sliding seat and "rows" by pulling on a handle connected to one end of the chain. A one-way clutch allows the chain to be spring-returned without interfering with the flywheel rotation.
While the above device provides accurate and repeatable resistance, it is not possible to use a true sweeping motion, so the sensation is not truly that of rowing or sculling. Moreover, because the hands are kept together on the handle, and are not spread at the beginning and end of each stroke, this machine does not exercise all of the muscle groups that are used in rowing, particularly those of the chest and shoulders.